In the standard VPS procedure the proximal part of the shunt is first placed in one of the lateral ventricles. The distal part of the shunt is then tunneled subcutaneously from the head to the abdomen, where 20-25 cm of the distal catheter and the tip are introduced in the peritoneal cavity through a paraumbilical mini-laparotomy. The intraperitoneal placement of the distal catheter is performed blindly, whereby the tip of the catheter is directed caudally in direction of the pelvis in order to avoid kinking and potential strangulation of the catheter. In this setting the functionality of the system can be estimated by feeling the resistance to out- and inflow while manually pumping the reservoir near the valve at the cranial level.